Introduction
Podcasting is the distribution of media files using web based syndication to iPod type devices. Podcasts need not just be for entertainment. As well as obvious training applications, they can have industrial uses. One is in the area of security.
Aerial Common Sensor program terminated
The US Defence Department's Aerial Common Sensor program (ACS) has been terminated at a cost of $US200M ("USA Restarts Sensor Quest", Stephen Trimble, Flight International, 24-30 January 2006). It was discovered that the Embraer ERJ-145 business jet which was to carry the sensors was not large enough to fit the equipment, or provide it with power and cooling.
The obvious solution to having an aircraft too small, is to use a larger one which fit everything in. But another alternative the US military is looking at is to make room by leaving out the crew. An Unmanned Aerial Vehicle (UAV) would be used for surveillance with the data transmitted to remote operators. One possibility is the General Atomics Warrior (based on the successful Predator UAV). Apart from the problem that these UAVs are even smaller than the original Embaraer aircraft, they would need to transmit more data.
One manned surveillance aircraft would typically be replaced by several UAVs. Each of these would need to transmit data to a human operator on the ground, or in another aircraft. This suggests that more data would need to be transmitted, with a larger antenna needed on each aircraft.
Research has been done on higher speed links for fighter aircraft ("Missing Link", by Stephen Trimble, Flight International, 24-30 January 2006). These are investigated in the Tactical Targeting Network Technology (TTNT) DARPA funded project achieving 10Mb/s. Higher speeds of 80 Mb/s to 300 Mb/s (up to 8 Gb/s) are achievable by using the Aircraft's electronically scanned array (AESA) radar as a radio transceiver. This is an alternative for the F-22 Raptor instead of low speed Link 16 data transmission.
Bandwidth Bottleneck
However, high bandwidth transmission will not always be possible. Even if an AESA radar is available, its use will be limited on a stealth aircraft. Also the radar is primarily designed to transmit to the front of the aircraft (some Russian fighters have a read mounted radar was well). Therefore an aircraft approach a target will have limited scope to transmit data back to from friendly territory behind it. Also not all platforms will have the new needed communications equipment.
High data transmissions also have to be received and processed to be of use. Multiple 8 Gb/s data streams are likely to overwhelm the capabilities of airborne manned centers and all but the largest ground based ones. Processing will need to be done on the data to turn it into useful information, before human operators can make decisions based on it.
Flying Podcasts to get out of bandwidth bottleneck
An alternative would be to place more data processing and some limited automated decision making in the surveillance platform. It can then decide what data needs to be transmitted using the available limited bandwidth. Decision can be made based on polices sent to the UAV. Human operators can request further details and higher resolution imagery, when the UAV alerts them to something of interest.
The usual military research approach to such a requirement would be to build specialized protocols and systems. An alternative would be to place a web server in the UAV. This would use common web protocols such as RSS/ATOM to alert operators to what is of interest. Operators would subscribe to feeds on topics of interest and then would receive imagery as Podcasts from the aircraft. This would allow much smaller UAVs to be used, such as the Aerosonde, and much simpler control centers.